prog.c

   1 /*
   2  * Copyright 2005 Timo Hirvonen
   3  */
   4
   5 #include "prog.h"
   6
   7 #include <stdlib.h>
   8 #include <stdio.h>
   9 #include <string.h>
  10 #include <stdarg.h>
  11 #include <errno.h>
  12
  13 char *program_name = NULL;
  14
  15 void warn(const char *format, ...)
  16 {
  17         va_list ap;
  18
  19         fprintf(stderr, "%s: ", program_name);
  20         va_start(ap, format);
  21         vfprintf(stderr, format, ap);
  22         va_end(ap);
  23 }
  24
  25 void warn_errno(const char *format, ...)
  26 {
  27         int e = errno;
  28         va_list ap;
  29
  30         fprintf(stderr, "%s: ", program_name);
  31         va_start(ap, format);
  32         vfprintf(stderr, format, ap);
  33         va_end(ap);
  34         fprintf(stderr, ": %s\n", strerror(e));
  35 }
  36
  37 void __NORETURN die(const char *format, ...)
  38 {
  39         va_list ap;
  40
  41         fprintf(stderr, "%s: ", program_name);
  42         va_start(ap, format);
  43         vfprintf(stderr, format, ap);
  44         va_end(ap);
  45         exit(1);
  46 }
  47
  48 void __NORETURN die_errno(const char *format, ...)
  49 {
  50         int e = errno;
  51         va_list ap;
  52
  53         fprintf(stderr, "%s: ", program_name);
  54         va_start(ap, format);
  55         vfprintf(stderr, format, ap);
  56         va_end(ap);
  57         fprintf(stderr, ": %s\n", strerror(e));
  58         exit(1);
  59 }
  60
  61 static int short_option(int ch, const struct option *options)
  62 {
  63         int i;
  64
  65         for (i = 0; ; i++) {
  66                 if (!options[i].short_opt) {
  67                         if (!options[i].long_opt)
  68                                 die("unrecognized option `-%c'\n", ch);
  69                         continue;
  70                 }
  71                 if (options[i].short_opt != ch)
  72                         continue;
  73                 return i;
  74         }
  75 }
  76
  77 static int long_option(const char *opt, const struct option *options)
  78 {
  79         int len, i, idx, num;
  80
  81         len = strlen(opt);
  82         idx = -1;
  83         num = 0;
  84         for (i = 0; options[i].short_opt || options[i].long_opt; i++) {
  85                 if (options[i].long_opt && strncmp(opt, options[i].long_opt, len) == 0) {
  86                         idx = i;
  87                         num++;
  88                         if (options[i].long_opt[len] == 0) {
  89                                 /* exact */
  90                                 num = 1;
  91                                 break;
  92                         }
  93                 }
  94         }
  95         if (num > 1)
  96                 die("option `--%s' is ambiguous\n", opt);
  97         if (num == 0)
  98                 die("unrecognized option `--%s'\n", opt);
  99         return idx;
 100 }
 101
 102 int get_option(char **argvp[], const struct option *options, char **arg)
 103 {
 104         char **argv = *argvp;
 105         const char *opt = *argv;
 106         int i;
 107
 108         *arg = NULL;
 109         if (opt == NULL || opt[0] != '-' || opt[1] == 0)
 110                 return -1;
 111
 112         if (opt[1] == '-') {
 113                 if (opt[2] == 0) {
 114                         /* '--' => no more options */
 115                         *argvp = argv + 1;
 116                         return -1;
 117                 }
 118                 i = long_option(opt + 2, options);
 119         } else if (opt[2]) {
 120                 return -1;
 121         } else {
 122                 i = short_option(opt[1], options);
 123         }
 124         argv++;
 125         if (options[i].has_arg) {
 126                 if (*argv == NULL)
 127                         die("option `%s' requires an argument\n", opt);
 128                 *arg = *argv++;
 129         }
 130         *argvp = argv;
 131         return i;
 132 }